I am not a Canuck, but it is extremely doubtful that you will find a direct flight to Opole unless it is a charter flight. You should look at flights to the major air hubs in Europe, and especially Polish airlines, LOT. Check the online airfare sites for the best deals, Expedia.com, travelocity.com, hotwire.com. (There are others.) Airfares usually go down in September. I suspect that your best bet is to fly into Warsaw, Krakow in Poland, or possibly Frankfurt in Germany and then take a train. Unlike in North America, the Europeans, and the Germans in particular, have excellent rail service. Train travel is almost always cheaper than airfare, the trains tend to run more frequently, and you can see more of Europe than just the airports! Overnight trains are also worth considering since they save a night's lodging expense. Check out the Eurorail website for info.

Unless you already have a work visa, I don't recommend a one-way flight. It could cause you trouble getting through customs, and at some point in time, you will want to return to Canada, eh? Last I looked, British Airlines had offered the longest possible stay on cheap airfare. If you do not have a work permit in Poland and you are traveling alone, DO NOT GO THROUGH CUSTOMS IN BRITAIN!!!